31421328 has 20 divisors (see below), whose sum is σ = 81171888. Its totient is φ = 10473760.

The previous prime is 31421311. The next prime is 31421329. The reversal of 31421328 is 82312413.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 31421298 and 31421307.

It is not an unprimeable number, because it can be changed into a prime (31421329) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 327258 + ... + 327353.

Almost surely, 2^31421328 is an apocalyptic number.

It is an amenable number.

31421328 is an abundant number, since it is smaller than the sum of its proper divisors (49750560).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31421328 is a wasteful number, since it uses less digits than its factorization.

31421328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 654622 (or 654616 counting only the distinct ones).

The product of its digits is 1152, while the sum is 24.

The square root of 31421328 is about 5605.4730398067. The cubic root of 31421328 is about 315.5548397201.

The spelling of 31421328 in words is "thirty-one million, four hundred twenty-one thousand, three hundred twenty-eight".